The present invention relates to a semiconductor device and a method of manufacturing the semiconductor device.
Non-volatile semiconductor memory devices have been known as a sort of semiconductor devices. As the non-volatile semiconductor memory device, flash memories have been known.
Japanese Unexamined Patent Publication No. 2009-44164 discloses a split gate non-volatile memory cell. The cell has a select gate above a portion of a channel region, a floating gate above other portion of the channel region, a control gate over the floating gate, and an erase gate adjacent the floating gate. The erase gate has an overhang extending over the floating gate.
Further, Japanese Unexamined Patent Publication No. Hei 7 (1995)-221206 discloses that one of upper edge portions of a floating gate that covers a control gate is fabricated acutely by isotropic etching.
Further, Japanese Unexamined Patent Publication No. 2006-108668 discloses a semiconductor device. The semiconductor device has an insulated floating gate provided over a semiconductor substrate, an insulated program gate formed over at least a lateral side of the floating gate, and an insulated erase gate provided adjacent the floating gate.